Modular terminal block assembly



April 18, 1967 E. R. KULKA MODULAR TERMINAL BLOCK ASSEMBLY Filed April3, 1964 .FIG.,6. 2: 4.2%]!

I NVEN TOR.

EUGfNE 1?. KUL (A BY arron AIL-ya E drawbacks and disadvantages.

Patented Apr. 18, 1967 3,315,215 MODULAR TERMINAL BLOCK ASSEMBLY EugeneR. Kulha, It Tamerton St., Mount Vernon, NY. 10552 Filed Apr. 3, 1964,Ser. No. 357,051 8 Claims. (Cl. 339-126) The present invention relatesgenerally to improvements in electrical connecting devices, and itrelates in particular to an improved terminal block of modularconstruction.

The conventional terminal block, although widely used in many types ofelectrical assemblies, possesses many The terminal block generallyincludes a strip or bar of insulating material provided with aperturedend wings to facilitate the mounting thereof. A plurality oflongitudinally spaced terminal members are mounted on the strip and eachusually includes a tapped base plate provided with a connector lug and ascrew engaging the tapped base plate and registering with acorresponding opening formed in the insulator strip. Successiveterminals are frequently separated by intervening vertical partitions,or barriers formed integrally with the insulator strip. The cost ofthese insulator blocks is high by reason of the fact that the blockbodies are initially molded of thermosetting plastic such as phenolicresins, in the form of long strips having, for example, thirty terminalstations separated by barrier walls, and these strips must be cut downto provide the number of stations required. The cutting is accomplishedby a rotating Carborundum wheel which, because of its thiclo ness,grinds away approximately one-eighth inch of plastic at the cut, leavinga rough surface on each cut end and often cutting into the barrier. Bothcut ends then require sanding to provide a smooth finish and the sandedends provide a porous surface which often requires sealing by a varnishcoating. The manufacturing operation is thus wasteful, time-consumingand expensive.

A further drawback of the conventional terminal block is its relativelylow breakdown or arcing voltage by reason of the small unimpeded airspace between the terminals or terminal screws and the underlyingmounting plates or surfaces. In addition, the mounting of theconventional terminal block is often difficult and these terminal blocksotherwise leave much to be desired.

It is, therefore, a principal object of the present invention to providean improved electrical connector.

Another object of the present invention is to provide an improvedterminal block.

Still another object of the present invention is to provide an improvedterminal block having an adjustable number of terminals.

A further object of the present invention is to provide a terminal blockmodular unit which may be assembled in preselected numbers to formcorresponding terminal blocks of the desired length.

Still a further object of the present invention is to provide animproved device of the above nature characterized by its versatility,low cost, ease of use and assembly and superior electrical properties.

In accordance with the present invention there is provided a modularterminal block assembly comprising a mounting member or panel having anelongated slot formed therein, a plurality of modules insertible withinsaid slot and having complementary depressions and projections forinterlocking the modules in an abutting line within the slot. Eachmodule includes an insulator block having an upper section located abovethe mounting panel and a lower section located beneath the panel andseparated from the upper section by a shoulder resting on'the topsurface of the panel. Each insulator block has a through bore extendingthrough the upper and lower sections thereof, and a terminal membermounted at the top of the bore. The terminal member includes a screw,the free end of which is spaced a substantial distance above the bottomof the lower section. The line of interlocked modules are secured withinthe slot by a spring clip frictionally engaging the lower section of atleast one of the modules and bearing on the bottom surface of themounting panel.

The above and other objects of the present invention will becomeapparent from a reading of the following description, taken inconjunction with the accompanying drawing, wherein:

FIG. 1 is a top plan view of a pair of terminal block modules embodyingthe present invention illustrated in disassembled condition in amounting panel; b1 FiG. 2 is a top plan view of the assembled terminalFIG. 3 is a front elevational view thereof, the mounting panel beingshown in section;

FIG. 4 is a bottom fragmentary plan view thereof;

FIG. 5 is a sectional view taken along line 55 in FIG. 3;

FIG. 6 is a sectional view taken along line 6-6 in FIG. 1; and

FIG. 7 is a transverse vertical sectional view of another form of moduleembodying the present invention.

Referring now to the drawings, and particularly FIGS. 1 to 6 thereofwhich illustrate a preferred embodiment of the present invention, thereference numeral 10 generally designates the improved terminal blockassembly which includes a mounting panel 11 and a connector moduleassembly 12. It should be noted that while the terminal block assembly19) is illustrated as containing four connector modules, it may containany desired number thereof. The mounting plate 11 may be formed of anydesired material, such as metal, plastic or the like, and may constitutethe wall of a cabinet, or housing or any part of the electricalequipment associated with the terminal block assembly It), or it mayconstitute a separate member. Formed in the panel 11 is a longitudinallyextending rectangular slot 13 which is substantially coextensive withthe module assembly 12. The module assembly 12 registers with the slot13 and is locked therein in the manner hereinafter set forth.

The module assembly 12 is formed of a plurality of interlockingend-to-end terminal units or modules including the single-partitionedmodules 14 and a double-partitioned module 16. Each of the modules 14comprises a block 17 formed of any suitable insulating material such ascommonly employed, synthetic organic thermosetting or thermoplasticresins, and includes integrally formed upper and lower sections 18 and19 respectively. The upper insulator block section 18 is of trapezoidalvertical transverse cross-section having a base width greater than thatof slot 13. The block lower section 19 includes a cylindrical member 20depending below panel 11 and having an enlarged shallow substantiallysquare upper part 21 of approximately the width of slot 13 andregistering therewith. The block upper and lower sections 13 and 1-9 areseparated along their front and rear by transversely spacedlongitudinally extending downwardly facing horizontal shoulders 22 whichrest on the upper longitudinal border-s of slot 13.

Formed on one of the end faces 23 of each of the insulator block uppersections 13 is a pair of transversely spaced longitudinally directedprojections 24 in the shape of hemispherical knobs or bosses. The otherend of the insulator block upper section is provided with an integrallyformed substantially rectangular vertical panel 26 delineating apartition or divider. The panel 26 is of greater width and height thanthe upper body section 13, projecting above and transversely beyond saidupper section 18 and having a lower edge at the level of shoulder 22. Apair of transversely spaced hemispherical depressions 27 are formed inthe outer face of panel 26 and are of a shape complementing projections24 and mate the projections 24 of an adjacent module 14. The depressions27 are at the level of and in longitudinal alignment with thecorresponding projections 24.

A vertical axial bore 28 is formed in each of the insulator blocks 17and terminates at its top in a bore of reduced diameter delineated frombore 28 by a downwardly directed peripheral shoulder. An internallythreaded metal bushing 29 registers with the bore of reduced diameterand is provided at its top with an integral 1y formed square plate orflange 30 abutting the top face of insulator block 17. The bottom of thebushing 29 is upset, as at 32, to engage the bore shoulder and firmlylock bushing 29 to insulator block 17. A metal screw 33 having afiat-bottomed slotted head 34 engages tapped bushing 29 and cooperateswith plate 30 to define a connector terminal.

The end module 16 is similar in construction to the modules 14,differing therefrom only in that the two end faces thereof are providedwith partition panels having coupling depressions formed therein.Specifically, module 16 comprises an insulator block 36 of the sameconfiguration as insulator block 17 but provided at both end faces withintegrally formed partition panels 37 of the shape of panel 26, each ofpanels 37 having formed in its outer face a pair of transversely spaceddepressions 38 corresponding to depressions 27 in shape and disposition.As in module 14, module 16 is provided with an electrical terminalmember 39.

In assembling terminal block 10, a module 16 and one or more modules 14,three in the illustrated embodiment, are pressed in end-to-endrelationship with their confronting end faces in substantial abutmentand the registering projections 24 and depressions 27 and 38, as thecase may be, in interlocking mating engagement. The resulting moduleassembly 12 is then brought into registry with matching slot 13,sections 21 engaging slot 13, shoulders 22 abutting the upper borders ofslot 13, and the cylindrical sections 20 projecting below slot 13. Themodule assembly 12 is then locked in slot 13, by means of a pair ofspring clips 40 engaging the cylindrical sections 20 of the endinsulator blocks and resiliently bearing on the underface of panel 11.The spring clips 40 may be of .the Tinnerman speed nut type or the likeand each includes a pair of end notched resilient legs 41 integrallyformed in a plate 42, the notched ends of legs 41 biting into theengaged cylindrical section 20.

It is clear from the above that merely by the provision of two types ofconnector modules, terminal blocks of any desired length may be rapidlyassembled at minimum cost and maximum convenience, the only variablebeing the length of mounting slot 13. This arrangement provides for thefurther advantages that the assembly and mounting of the terminal blockare simultaneously effected and the design and construction of theassociated equipment simplified and expedited since slot 13 may beformed in any suitable or desirable location. In addition, the improvedterminal block possesses a high breakdown voltage and surface leakagepath by reason of the great free air distance between the bottom ofterminal screw 33 and the ground as represented by panel 12 or clip 40since screw 33 is deeply recessed in the bore 28.

In FIGURE 7 of the drawing, there is illustrated an alternative form ofmodule 43 which may be employed to advantage in many applications. Themodule 43 diflfers from modules 14 and 16 earlier described Only in thesubstitution of a different type terminal member 44, for the bushing 29and the corresponding modification of the insulator block. The insulatorblock 46 is similar in shape to the insulator block 17 and has avertical axial bore 47 formed therein whose upper section is of lesserdiameter than its lower and is delineated therefrom by a downwardlyfacing peripheral shoulder. A cup-shaped socket member 48 having atapped axial bore telescopes the upper bore section and is provided withan outwardly directed square upper fiange 45 abutting the top face ofinsulator block 46. The bottom of the socket member 48 has a peripherallip 49 formed thereon which engages the bore separating shoulder to locksocket member 48 to insulator block 46.

Depending from the socket member 48 and integrally formed therewith is asolder lug defining axial post 50 projecting below insulator block 46and terminating in an enlarged head 51. A headed screw member 52 engagesthe tapped bore in socket member 48. In all other details, connectormodule 43 is similar in structure to modules 14 and 16 and a pluralitythereof are assembled and employed in the manner of modules 14 and 16,as earlier set forth.

While there have been described and illustrated preferred embodiments ofthe present invention, it is apparent that numerous alterations,omissions and additions may be made without departing from the spiritthereof.

What is claimed is:

1. A terminal block assembly for use with a panel having a top andbottom surface and a longitudinally extending slot formed therein, saidassembly comprising a plurality of end-to-end connector modulesregistering with said slot, each of said modules including a block ofinsulating material having opposite end faces provided withcomplementary projections and depressions and upper and lower sectionsseparated by downwardly directed longitudinal shoulders engaging theupper longitudinal borders of said slot, and a terminal member carriedby each of said insulator blocks, the projections and depressions of theconfronting end walls of successive modules being in mating engagementfor interlocking said modules in abutting alignment, said lower sectionincluding a cylindrical portion extending beneath said panel, and aspring clip engaging the cylindrical portion of at least one of saidmodules and bearing upon the bottom surface of said panel for immovablysecuring the aligned and interlocked modules to said panel.

2. The terminal block assembly of claim 1, wherein each of saidinsulator blocks has a vertical bore formed therein and extendingthrough said upper and lower sections, and in Which said terminal membercomprises a tapped tubular member positioned in the upper section ofsaid bore and a screw engaging said tapped tubular member with the freeend of said screw spaced a substantial distance from the bottom end ofsaid cylindrical portion.

3. The terminal block assembly of claim 2, wherein said tapped tubularmember is provided with an upper peripheral flange superimposed on thetop face of said insulator block, and wherein said vertical bore has adownwardly directed shoulder spaced inwardly from its top end, thebottom end of said tapped tubular member being upset to engage said boreshoulder.

4. The terminal block assembly of claim 1, including a transverselyextending vertical partitioning panel of insulating material formedintegrally with each of said insulator blocks adjacent an end thereofand projecting above the top face of said insulator block.

5. A connector module comprising a block of insulating material havingopposite end faces provided with complementary matable alignedprojections and depressions and having a vertical bore formed therein, atubular extension depending from said block and having an axial borecommunicating with the vertical bore of said block, and an electricalterminal mounted at the top end of said block and registering with saidvertical bore and including a tapped bushing and a screw engaging saidtapped bushing, the free end of said screw extending into said verticalbore and terminating short of the communicating bore of said extension.

6. A connector module comprising a block of insulating material havingopposite end faces provided with complementary matable alignedprojections and depressions and including upper and lower sectionsseparated by downwardy facing opposite longitudinally extendingshoulders, and an electrical terminal located on said insulator block,said lower section including a depending cylindrical end portion, saidblock having a vertical bore extending through the upper and lowersections, said electrical terminal including a tapped bushing mounted atthe upper end of said bore and a screw mounted in said tapped bushing,the free end of said screw extending into said bore and being spaced asubstantial distance from the bottom end of said cylindrical portion.

7. A connector module for use with a mounting member having anoncircular aperture therein, said connector module comprising a blockof insulating material having opposite end faces provided withcomplementary matable aligned projections and depressions, said blockcomprising an upper section of greater area than said mounting memberaperture and a lower section insertible through said aperture andforming a downwardly-facing shoulder with said upper section, at least aportion of said lower section being of noncircular cross-section andbeing located within the noncircular aperture of said mounting memberwhen the lower section is inserted through said aperture until saidshoulder is seated on said mounting member, thereby to restrain rotationof said module relative to the mounting member, the remainder of saidlower section projecting a substantial distance below said mountingmember, an electrical terminal located on the top surface of said uppersection, and a spring clip engaging the downwardly-projecting portion ofsaid lower section and bearing on the underface of said mounting member.

8. A terminal block assembly comprising a panel having top and bottomsurfaces and an elongated slot formed therein, a plurality of connectormodules sized for mounting within said slot with said modules abuttingeach other and arranged in a line coaxial with said slot, each of saidmodules comprising a block of insulating material having opposite endfaces provided with complementary projections and depressions, and upperand lower sections separated by downwardly directed lateral shoulders,each of said modules being insertible into said slot with the uppersection thereof projecting above said panel and said shoulders engagingthe upper surface of said panel at the longitudinal borders of saidslot, the projections and depressions of the confronting end walls ofsucces sive modules being located for mating engagement when saidmodules are in abutment for locking said modules in said line withinsaid slot, said lower section including a noncircular portion locatedwithin said slot, and a cylindrical portion depending from saidnoncircular portion and extending a substantial distance below thebottom surface of said panel, and clip means for frictional engagementwith the cylindrical portions of the two end modules in said line, saidclip means being adapted to abut the bottom surface of said panel forimmovably securing said line of interlocked modules within said slot.

References iited by the Examiner UNITED STATES PATENTS 2,701,870 2/1955Obszarny 339198 X 2,874,248 2/1959 Tondat et a1. 200-- 2,928,666 3/1960Gordon 339198 2,990,534 6/1961 Nielsen 339198 2,998,589 9/1961 Kulka339-498 FOREIGN PATENTS 931,803 "11/1947 France.

MARVIN A. CHAMPION, Primary Examiner. ALFRED S. TRASK, Examiner.

7. A CONNECTOR MODULE FOR USE WITH A MOUNTING MEMBER HAVING ANONCIRCULAR APERTURE THEREIN, SAID CONNECTOR MODULE COMPRISING A BLOCKOF INSULATING MATERIAL HAVING OPPOSITE END FACES PROVIDED WITHCOMPLEMENTARY MATABLE ALIGNED PROJECTIONS AND DEPRESSIONS, SAID BLOCKCOMPRISING AN UPPER SECTION OF GREATER AREA THAN SAID MOUNTING MEMBERAPERTURE AND A LOWER SECTION INSERTIBLE THROUGH SAID APERTURE ANDFORMING A DOWNWARDLY-FACING SHOULDER WITH SAID UPPER SECTION, AT LEAST APORTION OF SAID LOWER SECTION BEING OF NONCIRCULAR CROSS-SECTION ANDBEING LOCATED WITHIN THE NONCIRCULAR APERTURE OF SAID MOUNTING MEMBERWHEN THE LOWER SECTION IS INSERTED THROUGH SAID APERTURE UNTIL SAIDSHOULDER IS SEATED ON SAID MOUNTING MEMBER, THEREBY TO RESTRAIN ROTATIONOF SAID MODULE RELATIVE TO THE MOUNTING MEMBER, THE REMAINDER OF SAIDLOWER SECTION PROJECTING A SUBSTANTIAL DISTANCE BELOW SAID MOUNTINGMEMBER, AN ELECTRICAL TERMINAL LOCATED ON THE TOP SURFACE OF SAID UPPERSECTION, AND A SPRING CLIP ENGAGING THE DOWNWARDLY-PROJECTING PORTION OFSAID LOWER SECTION AND BEARING ON THE UNDERFACE OF SAID MOUNTING MEMBER.